Icon for a display screen



FIG. 1 is a front view of an icon for a display screen showing our new design; and,

FIG. 2 is a front view of an icon for a display screen showing an alternative embodiment of our new design.

The broken line showing of the display screen is for environmental purposes only and forms no part of the claimed design. 

The ornamental design for an icon for a display screen, as shown and described. 